Richie’s Fight for Life Foundation’s Fun Run is about a search for the reason a seven-year old boy is dying.

It’s about Richie Gonzales of Castaic, who loves superhero movies, video games and has a mom who refuses to stop looking for an answer to his mystery ailment.

“I wasn’t sure how I was going to accept that he couldn’t be cured when no one could explain why,” said Vanessa Palacio, Richie’s mother. “Nobody could explain the why.”

Richie has what’s called a multi-system disorder, which affects his heart, liver, kidneys, muscles, nerves, energy level and immune system.

He was born on Dec. 8, 2006, had his first surgery that New Year’s Eve, and his condition has progressively worsened.

He’s been declared terminal, but his mother won’t accept that or give up the fight to identify a specific problem so it can be addressed.

Richie lives with muscle deterioration, nerve pain and heart disease, along with other ailments. He’s had nine surgeries and his blood drawn 257 times.

The first-grader has seen about 35 specialists and been tested repeatedly, his mom says, but still has no classified diagnosis.

On the rare days Richie is physically up to it, Palacio’s husband of about a year, Joe, takes him to the movies. Seeing “Captain America 2” is on his “to-do” list.

Also on that list is a lap around West Ranch High School’s track in a wheelchair Sunday during a fundraiser for him dubbed the Fun Run. He won’t have the energy to stay the whole day, his mom says, but it’s doubtful that will dampen his mood.

“He has one of those spirits that is extremely happy,” Palacio said. “He’s content with everything he has in this life. He loves life. ... He never complains about anything.”

The run is aimed at raising money to help Palacio pay for a new test Richie has taken — whole exome sequencing — which may allow doctors to finally diagnose him.

According to Baylor College of Medicine’s website, the test looks for variations in a patient’s DNA sequence as potential keys to unlocking the individual’s condition.

“Until they know what is causing (Richie’s health problems), they can’t stop it,” Palacio said. “Anytime there is a new test, I have to try.”

Richie took the test at the end of October with results expected soon. The cost of the test fluctuates between $10,000 and $15,000, and Palacio has already signed on to pay whatever insurance won’t cover.

“I will sign over my house (if I have to) — I don’t care,” Palacio said. “We don’t ever want to give up hope.”

Richie’s Fight for Life Foundation’s Fun Run runs 9 a.m.-1 p.m. Sunday at West Ranch High School. Entry fee is $15 per runner.